$PBHTC$	pool boiling heat transfer coefficient, kW/m2.K
$EG$	ethylene glycol
CNTs	carbon nanotubes
${\phi }_V$	volume concentration, %
${\phi }_m$	mass concentration, %
${\rho }_p$	the density of nanopowder, kg/m3
${\rho }_w$	the density of water, kg/m3
${\rho }_v$	the density of vapor, kg/m3
$L$	length of the boiling chamber, m
$W$	width of the boiling chamber, m
$H$	the height of the boiling chamber, m
$R_a$	arithmetical mean roughness value, μm
$q^{.}$	applied heat flux, kW/m2
$P$	electrical power, W
$D_{out }$	the outer diameter of the copper tube, m
$L_{tube}$	length of copper tube, m
$T_{top}$	the temperature at the top surface, °C
$T_{side}$	the temperature at the side surface, °C
$T_{bottom}$	the temperature at the bottom surface, °C
$T_{s,ave}$	average surface temperature, °C
$\Delta T_{sup}$	superheat temperature, K
$T_{sat}$	saturation temperature, °C
${\mu }_l$	the viscosity of the liquid, Pa.s
$h_{lv}$	latent heat of vaporization, kJ/kg
$\sigma$	surface tension, N/m
$C_{p,l}$	specific heat of the liquid, kJ/kg. K
$C_{sf}$	liquid–surface interaction coefficient
$P{r}_l$	liquid Prandtl number
$pr$	reduced pressure ratio
$F_p$, $F_q$, $F_{SR}$	constants in Gorenflo correlation.
Subscripts
V	volume
m	mass
p	powder
w	water
v	vapor
l	liquid
out	outer
s	surface
sup	superheat
sat	saturation
nf	nanofluid
0	reference condition